The A3421xKA and A3422xKA Hall-effect, direction-detection
sensors are a new generation of special-function integrated sensors that
are capable of sensing the direction of rotation of a ring magnet. These
transducers provide separate digital outputs that provide information on
magnet rotation speed, direction, and magnet pole count. These devices
eliminate the major manufacturing hurdles encountered in fine-pitch
direction-detection applications, namely maintaining accurate mechani-
cal location between the two active Hall elements. Here, the two Hall
elements are photolithographically aligned to better than 1
m, as
contrasted with 100
m or worse mechanical location tolerance when
manufactured discretely. These highly sensitive, temperature-stable,
magnetic transducers are ideal for use in digital-encoder systems in the
harsh environments of automotive or industrial applications. The
A3421xKA is a high-hysteresis device designed for low-resolution
pulse counting while the A3422xKA is a high-sensitivity device
optimized for use with high-density magnets.
The A3421xKA and A3422xKA monolithic integrated circuits
contain two independent Hall-effect latches whose digital outputs are
internally coupled to CMOS logic circuitry that decodes signal speed
and direction. Extremely low-drift BiCMOS circuitry is used for the
amplifiers to ensure symmetry between the two latches so that signal
quadrature can be maintained. An on-chip voltage regulator allows the
use of these devices from a 4.5 V to 18 V supply. Both devices have
standard open-collector outputs; the logic operation of both devices is
the same.
Two operating temperature ranges are provided; suffix `E' is for
the automotive and industrial temperature range of -40
C to +85C,
suffix `L' is for the automotive and military temperature range of
-40
C to +150C. The 5-pin `KA' SIP package provides a cost-com-
petitive solution to linear magnetic sensing in harsh environments.
FEATURES
I
Internal Direction-Decoding Circuitry
I
Two Matched Hall Latches On A Single Substrate
I
Superior Temperature Stability
I
4.5 V to 18 V Operation
Electrically Defined Power-On State
Under-Voltage Lockout
HALL-EFFECT,
DIRECTION-DETECTION SENSORS
Always order by complete part number, e.g., A3421EKA .
X
V
CC
1
4
3
2
5
Dwg. PH-015
SUPPLY
DIRECTION
GROUND
E1 OUTPUT
SPEED
LOGIC
X
E1
E2
Pinning is shown viewed from branded side.
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, V
CC
. . . . . . . . . . . . . 18 V
Magnetic Flux Density, B . . . . Unlimited
Output OFF Voltage, V
OUT
. . . . . . . . V
CC
Output Sink Current, I
OUT
. . . . . . . 30 mA
Package Power Dissipation,
P
D
. . . . . . . . . . . . . . . . . . . . . . 500 mW
Operating Temperature Range, T
A
Suffix `EKA' . . . . . . . -40C to +85C
Suffix `LKA' . . . . . . -40C to +150C
Storage Temperature Range,
T
S
. . . . . . . . . . . . . . . -65C to +170C
3421
AND
3422
PRELIMINARY INFORMATION
(subject to change without notice)
September 6, 2000
Data Sheet
27650.1
3421
AND
3422
HALL-EFFECT,
DIRECTION-DETECTION
SENSORS
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
A3421xKA
A3422xKA
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Min.
Typ.
Max.
Units
Operate Point
B
OP
T
A
= -40
C
140
185
300
--
29
85
G
T
A
= +25
C
130
160
280
--
29
75
G
T
A
= Maximum
120
--
260
--
--
75
G
Release Point
3
B
RP
T
A
= -40
C
-300
-190
-140
-85
-19
--
G
T
A
= +25
C
-280
-175
-130
-75
-18
--
G
T
A
= Maximum
-260
--
-120
-75
-16
--
G
Hysteresis
B
hys
T
A
= -40
C
280
375
--
10
48
--
G
T
A
= +25
C
260
335
--
10
46
--
G
T
A
= Maximum
240
--
--
10
--
--
G
Operate Differential
B
OP1
- B
OP2
--
--
80
--
--
60
G
Release Differential
B
RP1
- B
RP2
--
--
80
--
--
60
G
MAGNETIC CHARACTERISTICS over operating voltage range.
NOTES: 1. Magnetic flux density is measured at most sensitive area of device,
nominally located 0.014" (0.37 mm) below the branded face of the package.
2. Typical Data is at V
CC
= 12 V and T
A
= +25
C and is for design information only.
3. As used here, negative flux densities are defined as less than zero (algebraic convention).
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